1. Field of the Invention
This invention relates to a disc playing apparatus, in which a disc inserted through a disc inserting slot is brought to and held on a turntable for playing back data with an optical pick-up, and is then released from the turntable and forced back to the outside of the disc inserting slot.
2. Description of the Prior Art
A disc playing apparatus for playing data recorded on a disc, such as a CD, a VCD, a DVD and a CD-ROM, has a mechanism for transferring a disc between the disc inserting slot and a turntable and also a mechanism for causing the disc to be held on and released from the turntable.
A well-known system in which these mechanisms are motor driven, are disclosed in Japanese Patent Publication No. 7-19418. This system has a drive member, which has a pair of cam grooves, i.e., one for transferring a disc and one for securing the disc to disc drive means, and a lever which couples the disc transfer cam groove and a disc holder member to each other. The drive member is linearly displaced with rotation of a motor, whereby the disc holder member is displaced by the disc transfer cam groove, and the disc is set on and released from the disc drive means by the cam groove for securing the disc to the disc drive means.
In this prior art apparatus, the two different cam grooves are sequentially made operative by utilizing the linear displacement of the drive member. The linear displacement, therefore, should be at least the sum of the displacement necessary for the disc transfer and the displacement necessary for securing the disc to the disc drive means. In addition, with a protuberance provided on the lever at an end thereof and engaged in a cam groove, a linear displacement of an inclined portion of the cam groove is converted into a corresponding rocking movement of the lever, which is in turn converted into a linear displacement of the disc holder member. Therefore, setting a gentle inclination angle of the inclined portion of the cam groove to the moving direction of the drive member, results in an increased linear displacement thereof. On the other hand, approaching the inclination angle to 90.degree. increases the width direction size of the drive member to increase the motor load.
An object of the invention is to provide a disc playing apparatus, which can highly accurately control the timings of causing the disc transfer and the holding and releasing of the disc on and from the turntable, while being small in size, simple in construction and inexpensive.